 measur oxygen tension cerebr tissu rat expos high pressur oxygen brain cerebrospin oxygen tension measur rat breath air high pressur oxygen ohp addit 5 percent co2 inspir oxygen rais cerebr oxygen tension rat expos 2 atm ab inhibit 75 hemoglobin satur para-aminopropriophenon lower cerebr po rat breath air rat expos ohp rate rise cerebr po steadi level rapid compress faster rate fall steadi level decompress addit inspir ga mixtur increas rate rise cerebr po anesthet urethan pentobarbit sodium affect cerebr po rat breath air oxygen 4 atm discuss relat factor contribut oxygen poison high pressur 